CVE-2023-21055
📋 TL;DR
This CVE describes a use-after-free vulnerability in the Android kernel's DIT (Data Interface Technology) driver due to a race condition in the dit_hal_ioctl function. It allows local privilege escalation to System level without requiring user interaction. Only Android devices with vulnerable kernel versions are affected.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
An attacker with local access gains full System privileges, potentially compromising the entire device, accessing sensitive data, installing persistent malware, or bypassing security controls.
Likely Case
Local privilege escalation allowing an attacker to elevate from a lower-privileged context to System level, enabling further exploitation or persistence.
If Mitigated
With proper kernel hardening, SELinux policies, and minimal privilege principles, impact is limited to specific processes rather than full system compromise.
🎯 Exploit Status
Exploitation requires winning a race condition and bypassing kernel protections like KASLR. No public exploit code is known, but kernel vulnerabilities are often weaponized.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: March 2023 Android security patch level
Vendor Advisory: https://source.android.com/security/bulletin/pixel/2023-03-01
Restart Required: Yes
Instructions:
1. Check for Android system updates in Settings > System > System update. 2. Install March 2023 or later security patch. 3. Reboot device to apply kernel patch.
🔧 Temporary Workarounds
Disable DIT driver module
linuxRemove or blacklist the vulnerable DIT kernel module if not required
rmmod dit
echo blacklist dit >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Restrict physical access to devices and implement application allowlisting
- Use SELinux policies to restrict System privilege access and monitor for privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check kernel version and security patch date: Settings > About phone > Android version > Kernel version and Security patch levelCheck Version:
adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify security patch level is March 2023 or later: Settings > About phone > Android version > Security patch level📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs, suspicious ioctl calls to /dev/dit, privilege escalation attempts in audit logs
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="android_kernel" AND ("dit_hal_ioctl" OR "use after free" OR "kernel panic")